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 245 Part IV. AN A T O M Y. the fuperior or afeending branch of the hasmorrhoiport# bepatica, Juperior or minor, the trunk of which with and on the right, with the fecond branch of the is commonly known by the name of ftnus vcnx porta- dalis; rum. The other portion may be called vena porta vsn- mefaraica. This fecond branch is a little under the firft, or colica tralis, inferior or major. fomething more towards the right hand. The large trunk of the vena porta: inferior,, or ventra- anterior,beandnamed gajlro-colica, and is foon divided into lis, is fituated under the lower or concave fide of the li- Ittwomay one fuperior, the other inferior. ver, and joined by an anaftomofis to the finus of the vena Thebranches, fuperior branch of the vena gaftro-colica fends portas hepatica, between the middle and right extremity fmall veins to the head of the pancreas, and forms the of that finus. From thence it runs down a little obliquegaftrica, or gaftro-epiploica dextra, which goes ly from right to left-, behind or under the trunk of the vena from the pylorus to the great curvature of the ftomach, arteria hepatica, bending behind the beginning of the du- and communicates with the gaftrica finiftra. In its pafodenum, and under the head of the pancreas. the ftomach and omentum, and commuHaving reached to the head of the pancreas, this trunk fage it fupplies with the pylorica, coronaria ventriculi, fyc. lofes the general name of vena porta, and terminates in sicates inferior branch of the vena gaftro-colica, which three large principal branches, which are dillributed, by mayThebe called dextra, goes to the right portion of numerous ramifications, to the vifcera already named. colon; andcolica from thence to the upper part of that inThe firft branch is termed vena mefaraica, or inefaraica the major-, the fecond, fplenica ; and the third, hamorrboi- teftine, where it is divided archwife, and communicates with the right branch of the colica anterior, and with a dalis interna, or mefaraica minor. The vena mefaraica major appears to be a continuation branch of the vena caecalis. of the trunk of the vena portae inferior. The fplenica The trunk of the great mefaraic vein fends out fomeis a capital branch of that trunk ; and, the haemorrhoi- times, oppofite to the gaftrica, a particular branch to the dalis interna has fometimes a common* origin with the omentum, called epiploica dextra. But almoft immediately before it afeends over the mefenteric artery, it fplenica. The inferior vena porta:, before the formation of thefe produces two large branches very near each other, which three branches, fends off from the trunk feveral fmall pafs behind and under the artery, being diftributed to rami, which are commonly the venae cyfticse, .hepatica the jejunum and part of the ilium by numerous rarniiiminor, pylorica, duodenalis, and fometimes the gaftrica cations. redta, and coronaria ventriculi. Afterwards the trunk of th: mefaraic pafles over the All thefe fmall veins fometimes arife feparately; and, fuperior mefenteric artery, to which it adheres very clofein other fubjeds, fome of them go out by fmall common ly, and from the convex fide of its arch fends out feveral branches, almoft in the fame manner with the artery. trunks. The cyftic veins run along the .veficula fellis, from its From the concave fide of the mefaraic vein, a little neck to the bottom; and as they are often no more than below the origin of the fecond branch,, from the convex two in number, they are called cyjiica gemsUa. fide, arifes a branch, called vetia atcalis, which runs to The fmall hep:'tic vein is commonly a branch of one the baginning of the colon, crofiing one of the branches of the cyftica:. oPthe fuperior mefenteric artery. The vena pylorica arifes from the great trunk,, aimoft This c2:cal vein divides by two arches, the uppernioft oppofite to the origin of the cyftica:; and fometimes is of which communicates with the lower branch of the veonly a branch of the right gaftrica. It palTes-over the na gaftro-colica; the other, after having fent ramificapylorus to the Ihort arch of the ftomach, where it is tions to the inteftinum caecum and appendicula vermilbrjoined, by anaftomofis, with the coronaria ventriculi. mis, communicates below with the extremity of the The duodenal vein, commonly called vena intefinalis, great mefar^ic vein. goes out from the great trunk near the cyfticae, and fome- The fplenic vein is one of the three great branches of times from the. fmall common trunk of thefe veins. It the vena portae. It runs tranfverfely from the right to is diftributed chiefly to the inteftinum duodenum, and the left, firft under the duodenum, and then along the fends likewife fome rami to the pancreas. lower fide of the pancreas. The inferior vena portae, having given off the fplenica, In this courfe it gives off feveral veins, viz. the vena changes its name to that of mefaraica. Ox mefaraica ma- coronaria ventriculi, pancreaticae, gaftrica, or gaftro-epijor ; which often appears to be rather a continuation of ploica finiftra, and epiploica finiftra. It likewife often the trunk, than of one of the great branches. to the haemorrho.idalis interna, the third It bends toward the fuperior mefenteric artery, fend- gives origin branch of the vena portae. ing off two veins, and afterwards running up over that capital It terminates by a winding courfe, being artery, it accompanies it in thofe portions of the mefen- divided into feveral.afterwards that g j to .the fpleen ; one tery and mefdcolon which belong to the fmall inteftines, of which produces thebranches fmall veins called, by the ancients, the caecum, and right portion of the colon. vafa brevia. . The firft particular branch from this trunk is called The coronaria ventriculi runs along the fmall arch of vena colica. It goes out from the anterior part of the that vifeus toward the pylorus, where it joins and betrunk, before it joins the artery, and runs direrily to the comes continuous with the vena pylorica. Iirits paifage, middle of the colon, where it divides to the right and left, feveral rami to the fides of the ftomach. and forms arches. On the left hand, it communicates it gives The vena: pancreaticse are fevyal fmall branches Vol. I. No. it. g 5 CL ■ lent